Figure 26-1 Wave Fronts and Rays

Figure 26-2 Spherical and Planar Wave Fronts

Figure 26-3 Reflection from a Smooth Surface

Reflection Law of reflection  i  r

Figure 26-4 Reflection from Smooth and Rough Surfaces

Figure 26-6 Locating a Mirror Image

Figure 26-8 Spherical Mirrors

Figure 26-9 Concave and Convex Mirrors

Figure Parallel Rays on a Convex Mirror

Figure Parallel Rays on a Concave Mirror

Figure Spherical Aberration and the Parabolic Mirror

Figure Principal Rays Used in Ray Tracing for a Concave Mirror

Figure Principal Rays Used in Ray Tracing for a Convex Mirror

Figure Image Size and Location in a Convex Mirror

Figure Image Formation with a Concave Mirror

Example 26-3 Image Formation

Mirrors The mirror equation

Mirrors Magnification

Mirrors d o =distance of the object from the mirror d i =distance of the image from the mirror f= focal length of the mirror

Mirrors Distances in front of the mirror are positive. Distances behind the mirror are negative.

Table 26-1 Imaging Characteristics of Convex and Concave Spherical Mirrors Convex Mirror Object locationImage orientationImage sizeImage type ArbitraryUprightReducedVirtual Concave Mirror Object locationImage orientationImage sizeImage type Beyond CInvertedReducedReal CInvertedSame as objectReal Between F and CInvertedEnlargedReal Just beyond FInvertedApproaching infinityReal Just inside FUprightApproaching infinityVirtual Between mirror and FUprightEnlargedVirtual

Mirrors Mirror problems: 19, and on page 883. Ray tracing worksheet.

Refraction When light transitions between two media with different indices of refraction, it will change direction if it transitions at an angle to the demarcation between the two media.

Refraction Angles of incidence and angles of refraction are measured in reference to a line normal (perpendicular) to the line of demarcation between media.

The index of refraction (n) for a medium is defined as the speed of light in vacuum (c) divided by the speed of light in the medium(v).

Exercise 26-4 Find the angle of refraction

Refraction There is a mathematical relationship that is used to calculate the amount of bending called Snell’s Law.

Refraction

If a ray is transitioning from a medium of lesser n to a medium of greater n it will bend toward the normal.

Refraction If a ray is transitioning from a medium of greater n to a medium of lesser n it will bend away from the normal.

Figure Light Propagating Through a Glass Slab

Refraction Problems on page 883.

Lenses Refractive properties of materials are useful in manipulating light for imaging purposes through the use of lenses.

Lenses Lenses consist of two main types converging and diverging.

Figure A Variety of Converging and Diverging Lenses

Figure The Three Principal Rays Used for Ray Tracing with Convex Lenses

Figure The Three Principal Rays Used for Ray Tracing with Concave Lenses

Figure 26-35a Ray Tracing for a Convex Lens

Figure The Image Formed by a Concave Lens

Lenses The lens equation

Lenses Magnification

Lenses d o =distance of the object from the lens d i =distance of the image from the lens f= focal length of the lens

Lenses Focal length f is positive for converging(convex) lenses f is negative for diverging (concave) lenses Magnification m is positive for upright images (same orientation as the object) m is negative for inverted images (opposite orientation of object)

Lenses Image distance d i is positive for real images (on the opposite side of the lens from the object) d i is negative for virtual images (on the same side of the lens from the object) Magnification m is positive for upright images (same orientation as the object) m is negative for inverted images (opposite orientation of object)

Lenses d o is positive for real objects (from which light diverges) d o is negative for virtual objects (toward which light converges)

Lenses Problems on page 885. Ray tracing worksheet.

Dispersion of light The index of refraction in a substance is different for light of different frequencies.

Dispersion of light The greater the frequency, the greater the index of refraction.

Dispersion of light Violet light will bend more than red light or green light, and therefore a separation of colors occurs.

Example 26-8 Prismatics

Figure Dispersion in a Raindrop

Figure How Rainbows Are Produced

Dispersion of light Problem 77 on p 885